Final Physics 2

A ball is thrown vertically upwards. The upward direction is considered the positive direction. Assuming that air resistance is negligible, identify correct statement.

• When the ball is at the highest point,its acceleration is zero

• Its velocity is negative during the upward and downward motion.

• Its acceleration is negative during the upward and downward motion of the ball.

• Its displacement from the point of projection is negative during the upward and downward motion.

An athlete doing the long jump takes off at a speed of 12.0 ms-1 at an angle of 30^o to the horizontal. How far would be able to jump.

• 6.36 m

• 12.7 m

• 29.5 m

• 58.9 m

Identify Newton's First Law

• F=ma

• Every action has an equal and opposite reaction

• An object at rest stays at rest, an object in motion stays in motion.

• Friction

You are carrying a lunch tray when you bump into the edge of a table. Although the tray did not tip, your milk falls off of the front of the tray.

• Newton's

  1st

  Law of Motion

• Newton's

  2nd

  Law of Motion

• Newton's

  3rd

  Law of Motion

Tags

NGSS.MS-PS2-4

Newton's third law of motion is about ation and reaction. Which statement is not correct about the action and the reaction.

• They are in opposite directions

• They act on the same body

• They are the same type of force

• They have the same magnitude

A passenger of mass 55kg is in a car which is moving with a velocity of 20ms^-1. If the driver suddenly brakes the car, the passenger who is wearing a seat belt is pushed forward at the distance of 0.4 m.Find the average pulling force of the seat belt and the time interval of the force acting on the passenger. ( neglect the effect of friction between the passenger and the seat of the car).

• Average force = 1.1 x 10⁴ N, Time Interval = 0.03 s

• Average force = 2.2 x 10⁴ N, Time Interval = 0.05 s

• Average force = 2.8 x 10⁴ N, Time Interval = 0.04 s

• Average force = 5.6 x 10⁴ N, Time Interval = 0.02 s

Two wooden clock Q and R of masses 2.0kg and 1.5kg respectively are on a smooth table as shown in the figure. A force of 7.0N acts on the block Q so that both the block accelerate together.

Find the horizontal force that Q exerts on R.

• 1.0 N

• 3.0 N

• 4.0 N

• 7.0 N

Identify the energy change that occurs when a ball rolls down an inclined plane without slipping.

• Potential Energy ---> Translational kinetic Energy

• Potential Energy ---> Rotational kinetic Energy

• Potential Energy ---> Translational kinetic Energy + Rotational kinetic Energy

• Potential Energy ---> Translational kinetic Energy + Work done against friction

The S.I unit of the Stefan- Boltzmann constant is

• kgms^-2K^-4

• kg m^-1s³ K²

• kg^-1s²K^-2

• kg s^-3 K^-4

A refrigerator door is 120.0 cm high, 75.0 cm wide and 5.5 thick. The temperature of the inner and outer surface of the door are 0^oC and 32^oC respectively. Find the heat flow through the door in one minute.

(Thermal conductivity of the door is 0.21 W m^-1 K^-1)

• 4.80 x 10³ J

• 5.00 x 10³ J

• 5.81 x 10³ J

• 6.60 x 10³ J