Explanation

Momentum (p) is proportional to velocity (v), while kinetic energy (KE) is proportional to v².

When momentum decreases by 20%, velocity decreases by 20%.

So, kinetic energy decreases by (1 - 0.8²) × 100% ≈ 36%.

Explanation

Let's denote the weight of the man in the stationary lift as W and the weight in the accelerating lift as W'.

We know that W' / W = 2/3.

When the lift is accelerating downward with acceleration 'a', the apparent weight (W') is given by:

W' = W - ma

where m is the mass of the man.

Since W' / W = 2/3, we can write:

(W - ma) / W = 2/3

Substitute W = mg (where g is the acceleration due to gravity):

(mg - ma) / mg = 2/3

Simplify:

g - a = (2/3)g

a = g - (2/3)g

a = (1/3)g

a = g/3

Explanation

For maximum range, the angle of projection should be 45°.

However, since that's not an option, we need to find the angle closest to 45°.
Among the given options:

• - 35° is closer to 45° than 20°.
• - 60° is closer to 45° than 70°.

However, 35° is closer to 45° than 60°.
So, the correct answer is: 35°.

Explanation

Since the smaller part becomes stationary, it means that the larger part will carry all the momentum.

Let's say the mass of the smaller part is m and the mass of the larger part is 3m.

Initial momentum = Final momentum

mV + 3mV = 3mV'

where V' is the velocity of the larger part.

Combine like terms:

4mV = 3mV'

Divide both sides by 3m:

V' = 4V/3

Explanation

When a man throws a ball to the maximum height (h), the initial velocity (v₀) is entirely vertical.

The maximum height (h) is given by:

h = v₀² / (2g)

where g is the acceleration due to gravity.

Now, when the man throws the same ball to the maximum horizontal distance, the initial velocity (v₀) is entirely horizontal.

The maximum horizontal distance (R) is given by:

R = v₀² / g

Substituting the expression for v₀² from the first equation:

R = 2h

Explanation

The equivalent resistance (R_eq) of the parallel combination:

R_eq = (4 kΩ × 6 kΩ) / (4 kΩ + 6 kΩ) = 2.4 kΩ

The tolerance calculation:

Since both resistors have the same relative tolerance (10%), the resultant parallel combination will also have a tolerance close to 10%.

Explanation

Explanation

Explanation

Explanation