Explanation:
Gravitational potential energy
= mgh
= (2kg)(10N/kg)(5m)
= 100J.
Answer:
The Acceleration will increase
Explanation:
Newton's Second Law of motion: It states that the rate of change of momentum is directly proportional to the applied force and takes places along the direction of the force.
It can be expressed mathematically as,
F ∝ m(v-u)/t
Where (v-u)/t = a
F = kma.
F = force, m = mass of the body, a = acceleration, k = constant of proportionality which tend to unity for a unit force, a unit mass, and a unit acceleration.
Therefore,
F = ma.
From the equation above,
If the net force acting on a body increase, while the mass of the body remains constant, the acceleration will also increase.
Answer:
33.6 Ns backward.
Explanation:
Impulse: This can be defined as the product of force and time. The S.I unit of impulse is Ns.
From Newton's second law of motion,
Impulse = change in momentum
I = mΔv................................. Equation 1
Where I = impulse, m = mass of the skater, Δv = change in velocity = final velocity - initial velocity.
Given: m = 28 kg, t = 0.8 s, Δv = -1.2-0 = -1.2 m/s (Note: the initial velocity of the skater = 0 m/s)
Substituting into equation 1
I = 28(-1.2)
I = -33.6 Ns
Thus the impulse = 33.6 Ns backward.
Answer: 
Explanation:
Given
Mass of the elevator is 
Time period of ascension 
cruising speed 
Distance moved by elevator during this time
Suppose Elevator starts from rest

Distance moved

Gain in Potential Energy is

Average power during this period is

Answer:
A. Thermal energy will move from the water to the ice.
B. Thermal energy will move from air to the water.
C. Thermal energy will move from the ice to the air.
D. Thermal energy will move from the water to the air.
A and B are correct
Explanation:
Because thermal energy will move from the water to the ice