Projectile motion
In a normal projectile motion, which of the following quantities has an effect in calculating the body’s mass?
Force
A ball was spinning around on a string of a certain radius at a constant speed. Then it went around the same curve at half of the original speed. Which of the following correctly identifies the new force acting on the ball?
The new force exerted on the car towards the center of the curve was one-half as much as before.
Kids were playing with balls which are of equal mass. They kicked them with different forces. Which one accelerated more?
Red ball – 10N
Blue ball – 3N
Yellow ball -5N
A.None of the them
B.Yellow ball since force there is no relation between force and mass
C.Blue ball since force and acceleration are inversely related.
D.Red ball since force and acceleration are directly related.
C.Blue ball since force and acceleration are inversely related.
What is an object's change in momentum equal to?
the impulse acting on the object
What is the SI unit for acceleration?
m/s^2
In a normal projectile motion, what will be the condition for maximum range?
θ = 45°
What is another name for the first law of motion? Why is it given that name?
Law of inertia
It is given that name because inertia is the tendency of an object to resist any change in its motion until an unbalanced force acts on it. That is the same thing that Newton’s first law states.
A 5000kg truck and a 1000kg car are travelling at constant speeds and then collides. What is true about the Forces and acceleration on each?
A.5000kg truck exerts a greater force on the 1000kg car, but the acceleration will be same.
B.5000kg truck exerts a greater force on the 1000kg car, but the 5000kg truck will get a greater acceleration.
C.Since they are moving with a constant velocity, the Forces on each of them are equal. But the 1000kg car will have greater acceleration since it has less mass.
D.Both Forces and acceleration are different.
C.Since they are moving with a constant velocity, the Forces on each of them are equal. But the 1000kg car will have greater acceleration since it has less mass.
Two cars of equal mass (1100 kg) and speed (36 km/h) collide head on in a completely inelastic collision.
What is the vector sum of the momentum of the system of two cars after the collision?
0 kg.m/s
If a 15kg ball takes five seconds to strike the ground when released from rest, at what height was the ball dropped?
125m
If a golf ball is hit with more force at the same angle, its initial acceleration will increase, decrease, or remain the same?
Increase
Describe what happens if you are riding a skateboard and hit something (like a curb) with the front wheels.
1 st Law Your body will keep moving forward and fly off your skateboard since the curb only stops the board, not yourself
Which statement best describes what happens when forces are balanced?
A baseball (1kg) coming from the East is approaching Barry at 10 m/s. Barry hit the baseball back to where it came from and the baseball leaves his bat at 10 m/s. What is the impulse Barry delivered to the baseball?
20 N.s to the East
How long does it take an object to travel a distance of 30m from rest at a constant acceleration of 2m/s2?
5.5s
A cannon is fired horizontally from the top of a 30m cliff into the ocean. The initial velocity of the cannon was 1000m/s. How far from the cliff does the cannon ball hit the water?
2470 m
Describe why you hold your gun next to your shoulder while deer hunting
3 rd Law When you pull the gun’s trigger, it forces the bullet out of the gun, but at the same time, the gun is forced in the opposite direction of the bullet (towards you). Your shoulder is a new force that is introduced in order to keep your gun from flying away from you.
Which of the following is NOT a fundamental force of the universe?
D.mass
D.mass
When will the momentum of an isolated system remain conserved?
external force on the system is zero
How far will an object travel after ten seconds if it is dropped into a bottomless pit?
500m
A stone with an initial velocity of zero is dropped from a bridge above a river. After 3 s, the stone strikes the water below the bridge. Approximately how fast is the stone traveling when it strikes the water?
30 m/s
Using Newton’s laws explain why heavier objects require more force than lighter objects to move or accelerate them?
2 nd Law Something with more mass moving at the same acceleration as a lighter object would require more force to change its speed or change its direction. Our formula F=m x a is derived from Newton’s second law.
A straight wire 30.0 m long moves at 2.00 m/s perpendicularly through a 1.00 T magnetic field. What is the induced EMF
EMF=60V
If a small car with a mass of 800 kg is moving with a velocity of 27.8 m/s, then what is its momentum?
22,240 kg·m/s
Suppose that two people are ice skating. Person A has a mass of 100kg and person B has a mass of 50kg. At one point, both of them are standing on the ice together while not moving. If both of them push away from each other and slide across the frictionless ice, what will be the speed of person B compared to person A?
The speed of Person B will be twice as much as the speed of Person A