Physics

Marcia uses a bow to shoot an arrow with initial velocity of magnitude v0 and at an angle θ above the horizontal. When the arrow returns to the same height from which it started,A) the speed of the arrow is twice v0.B) the speed of the arrow is 9.8 times larger than v0.C) the speed …

Marcia uses a bow to shoot an arrow with initial velocity of magnitude v0 and at an angle θ above the horizontal. When the arrow returns to the same height from which it started, A) the speed of the arrow is twice v0. B) the speed of the arrow is 9.8 times larger than v0. C) the speed of the arrow is again v0. D) the speed of the arrow is sqrt(2)v0. E) the speed of the arrow is v0/sqrt(2) .Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30°. When the snowballs reach the ground below, A) Debra’s snowball will have a higher speed than Mary’s. B) Mary’s snowball will have a higher speed than Debra’s. C) Both snowballs will hit the ground with the same speed. D) Debra’s snowball never hits the ground since it is thrown upwards. E) Mary’s snowball never hits the ground since it is thrown downwards.A rock is thrown from ground level at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the magnitude of the velocity of the rock right before it hits the ground? A) It is equal to its initial vertical velocity. B) It is equal to its initial horizontal velocity. C) It is equal to the magnitude of its initial velocity. D) 0 E) Cannot be determined without additional information. Read More »

For which value of θ is the range of a projectile fired from ground level a maximum?A) 30° above the horizontalB) 45° above the horizontalC) 55° above the horizontalD) 60° above the horizontalE) 90° above the horizontal For which value of θ is the height of a projectile fired from ground level a maximum?A) 30° …

For which value of θ is the range of a projectile fired from ground level a maximum? A) 30° above the horizontal B) 45° above the horizontal C) 55° above the horizontal D) 60° above the horizontal E) 90° above the horizontal.For which value of θ is the height of a projectile fired from ground level a maximum? A) 30° above the horizontal B) 45° above the horizontal C) 55° above the horizontal D) 60° above the horizontal E) 90° above the horizontal.If the initial speed of a projectile is doubled. A) Its range will be increased by 1.41. B) Its range will double. C) Its range will be decreased by a factor of two. D) Its range will quadruple. E) Its range will decrease by a factor of four. Read More »

A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the monkey remains seated at the top of the tree, how should the …

A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the monkey remains seated at the top of the tree, how should the person aim the arrow containing the food so that the monkey gets the food? A) He should aim it at the monkey. B) He should aim it below the monkey. C) He should aim it above the monkey. D) None of the other choices is correct.A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food, how should the person aim the arrow containing the food? A) He should aim it at the monkey. B) He should aim it below the monkey. C) He should aim it above the monkey. D) None of the other choices is correct.A bullet is fired from ground level with a speed of 150 m/s at an angle 30.0° above the horizontal at a location where g = 10.0 m/s2. What is the horizontal component of its velocity when it is at the highest point of its trajectory? A) 0 m/s B) 10 m/s C) 75.0 m/s D) 130 m/s E) 150 m/s.A bullet is fired from ground level with a speed of 150 m/s at an angle 30.0° above the horizontal at a location where g = 10.0 m/s2. What is the vertical component of its velocity when it is at the highest point of its trajectory? A) 0 m/s B) 10 m/s C) 75.0 m/s D) 130 m/s E) 150 m/s Read More »

A rock is thrown upwards at an angle of 40° with respect to the horizontal. As the rock is rising in its trajectory, the horizontal component of its velocityA) increases.B) decreases.C) remains the same.D) is zero.E) Cannot be determined without additional information. A projectile is launched with an initial velocity of 80 m/s at an …

A rock is thrown upwards at an angle of 40° with respect to the horizontal. As the rock is rising in its trajectory, the horizontal component of its velocity A) increases. B) decreases. C) remains the same. D) is zero. E) Cannot be determined without additional information.A projectile is launched with an initial velocity of 80 m/s at an angle of 30° above the horizontal. Neglecting air resistance, what is horizontal component of the projectile’s acceleration? A) 80 m/s2 B) 40 m/s2 C) 9.8 m/s2 D) 0 m/s2 E) 4.9 m/s2.A boy kicks a football with an initial velocity of 20 m/s at an angle of 25° above the horizontal. The magnitude of the acceleration of the ball while it is in flight is A) 25 m/s2. B) 20 m/s2. C) 9.8 m/s2. D) 8.4 m/s2. E) 0 m/s2.An athlete throws a ball with a velocity of 40 m/s at an angle of 20° above the horizontal. Which of the following statements is true in this case? A) The vertical component of the velocity remains constant. B) The horizontal component of the velocity changes. C) The vertical component of the velocity changes sign after the ball attains its maximum height. D) The horizontal component of the velocity changes sign after the ball attains its maximum height. E) None of the given choices is correct. Read More »

A rock is thrown at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the velocity of the rock at the highest point of its trajectory?A) 0B) 9.8 m/sC) It is equal to its initial horizontal velocity.D) It is equal to its initial vertical …

A rock is thrown at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the velocity of the rock at the highest point of its trajectory? A) 0 B) 9.8 m/s C) It is equal to its initial horizontal velocity. D) It is equal to its initial vertical velocity. E) It is equal to its initial velocity.A student kicks a soccer ball in a high arc toward the opponent’s goal. At the highest point in its trajectory: A) both velocity and acceleration of the soccer ball are zero. B) neither the ball’s velocity nor its acceleration is zero. C) the ball’s acceleration is zero but not its velocity. D) the ball’s acceleration points upwards. E) the ball’s velocity points downwards.When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed? A) It is zero. B) It is less than its initial speed. C) It is equal to its initial speed. D) It is greater than its initial speed. E) Cannot be determined without additional information.A rock is thrown upwards at an angle of 40° with respect to the horizontal. As the rock is rising in its trajectory, the vertical component of its velocity A) increases. B) decreases. C) remains the same. D) is zero. E) Cannot be determined without additional information. Read More »

A mountain climber encounters a crevasse in an ice field. The opposite side of the crevasse is a height h lower, and is separated horizontally by a distance w. To cross the crevasse, the climber gets a running start and jumps in the horizontal direction. If the height of the crevasse increases but the width …

A mountain climber encounters a crevasse in an ice field. The opposite side of the crevasse is a height h lower, and is separated horizontally by a distance w. To cross the crevasse, the climber gets a running start and jumps in the horizontal direction. If the height of the crevasse increases but the width remains the same, then, A) the minimum speed needed to cross the crevasse increases. B) the minimum speed needed to cross the crevasse decreases. C) the minimum speed needed to cross the crevasse stays the same D) the minimum speed needed to cross the crevasse will depend on the mass of the mountain climber. E) the minimum speed needed to cross the crevasse will depend on the weight of the mountain climber.James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. When they reach the lake below, A) the splashdown speed of James is larger than that of John. B) the splashdown speed of John is larger than that of James. C) they will both have the same splashdown speed. D) the splashdown speed of James will always be 9.8 m/s larger than that of John. E) the splashdown speed of John will always be 25 m/s larger than that of John.James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below. A) James reaches the surface of the lake first. B) John reaches the surface of the lake first. C) James and John will reach the surface of the lake at the same time. D) Cannot be determined without knowing the mass of both James and John. E) Cannot be determined without knowing the weight of both James and John.A pilot drops a bomb from a plane flying horizontally at a constant speed. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will A) be behind the bomb. B) be over the bomb. C) be in front of the bomb. D) depend of the speed of the plane when the bomb was released. E) depend of the mass of the bomb when it was released. Read More »

For general projectile motion, the vertical component of a projectile’s accelerationA) is zero.B) remains a non-zero constant.C) continuously increases.D) continuously decreases.E) any of the above, depending on position. For a projectile launched horizontally, the vertical component of a projectile’s velocityA) is zero.B) remains a non-zero constant.C) continuously increases.D) continuously decreases.E) any of the above, depending …

For general projectile motion, the vertical component of a projectile’s acceleration A) is zero. B) remains a non-zero constant. C) continuously increases. D) continuously decreases. E) any of the above, depending on position.For a projectile launched horizontally, the vertical component of a projectile’s velocity A) is zero. B) remains a non-zero constant. C) continuously increases. D) continuously decreases. E) any of the above, depending on position.For a projectile launched horizontally, the horizontal component of a projectile’s velocity A) is zero. B) remains a non-zero constant. C) continuously increases. D) continuously decreases. E) any of the above, depending on position.A ball rolls off the edge of a table. The horizontal component of the ball’s velocity remains constant during its entire trajectory because A) the ball is not acted upon by any force. B) the net force acting on the ball is zero. C) the ball is not acted upon by a force in the horizontal direction. D) the ball is not acted upon by a force in the vertical direction. E) None of the other choices is correct. Read More »

If the acceleration of an object is always directed perpendicular to its velocity, thenA) the object is speeding up.B) the object is slowing down.C) the object is moving with a constant velocity.D) the object is turning.E) this situation would not be physically possible. You are trying to cross a river that flows due south with …

If the acceleration of an object is always directed perpendicular to its velocity, then A) the object is speeding up. B) the object is slowing down. C) the object is moving with a constant velocity. D) the object is turning. E) this situation would not be physically possible.You are trying to cross a river that flows due south with a strong current. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should head your motorboat A) due west. B) due north. C) due south. D) in a southwesterly direction. E) in a northwesterly direction.For general projectile motion, the horizontal component of a projectile’s velocity A) is zero. B) remains a non-zero constant. C) continuously increases. D) continuously decreases. E) any of the above, depending on position.For general projectile motion, the horizontal component of a projectile’s acceleration A) is zero. B) remains a non-zero constant. C) continuously increases. D) continuously decreases. E) any of the above, depending on position. Read More »

Under which of the following conditions would a car have a westward acceleration?A) As a car travels eastward with its velocity is increasing.B) As a car travels eastward with its velocity is decreasing.C) As a car travels westward with its velocity is decreasing.D) As a car travels westward with its velocity is constant.E) As a …

Under which of the following conditions would a car have a westward acceleration? A) As a car travels eastward with its velocity is increasing. B) As a car travels eastward with its velocity is decreasing. C) As a car travels westward with its velocity is decreasing. D) As a car travels westward with its velocity is constant. E) As a car travels eastward with its velocity is constant.A car travels along eastward with a constant velocity. The magnitude of the acceleration of the car is A) decreasing. B) increasing. C) non-zero constant. D) zero. E) None of the other choices is correct.If the acceleration vector of an object is directed parallel to the velocity vector, then A) the object is speeding up. B) the object is slowing down. C) the object is moving with a constant velocity. D) the object is turning. E) the object is at rest.If the acceleration vector of an object is directed anti-parallel to the velocity vector, then A) the object is speeding up. B) the object is slowing down. C) the object is moving with a constant velocity. D) the object is turning. E) the object is at rest. Read More »

Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the airA) 0.50 times as long.B) 1.41 times as long.C) twice as long.D) three times as long.E) four times as long. Two athletes jump straight up. John has twice the initial speed of Harry. Compared to …

Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the air A) 0.50 times as long. B) 1.41 times as long. C) twice as long. D) three times as long. E) four times as long.Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John jumps A) 0.50 times as long. B) 1.41 times as long. C) twice as long. D) three times as long. E) four times as long.Two objects are dropped from a bridge, an interval of 1.0 s apart. During the time that both objects continue to fall, their separation A) increases. B) decreases. C) stays constant. D) increases at first, but then stays constant. E) decreases at first, but then stays constant.From the edge of a roof top you toss a green ball upwards with initial velocity v0 and a blue ball downwards with the same initial velocity. When they reach the ground below, A) the green ball will be moving faster than the blue ball. B) the blue ball will be moving faster than the green ball. C) the two balls will have the same speed. Read More »