Answer:
The final velocity of the bullet is 9 m/s.
Explanation:
We have,
Mass of a bullet is, m = 0.05 kg
Mass of wooden block is, M = 5 kg
Initial speed of bullet, v = 909 m/s
The bullet embeds itself in the block which flies off its stand. Let V is the final velocity of the bullet. The this case, momentum of the system remains conserved. So,

So, the final velocity of the bullet is 9 m/s.
Answer:
7503.13 N/m
Explanation:
Use principle of conservation of energy.
Here, energy stored in the spring due to compression shall be utilized in attaining the potential energy of the mug.
Given that,
Length of the spring = 20 cm = 0.20 m
Compression, x = 8 cm = 0.08 m
mass of the mug, m = 350 g = 0.35 kg
h = 7 m
use the expression for energy balance -
(1/2)*k*x^2 = m*g*h
=> k = (2*m*g*h) / x^2
input the values
k = (2*0.35*9.8*7) / 0.08^2
= 7503.13 N/m
Answer:
There will be no change in the direction of the electric field .
Explanation:
The direction will remain the same because the sign of the charges has no effect on it.
When one replaces the conducting cube with one that has positive charge carriers there will be no change in the direction of the field as there is no defined relationship between the direction of the electric field and sign of the charge.
Answer:
d. 37 °C
Explanation:
= mass of lump of metal = 250 g
= specific heat of lump of metal = 0.25 cal/g°C
= Initial temperature of lump of metal = 70 °C
= mass of water = 75 g
= specific heat of water = 1 cal/g°C
= Initial temperature of water = 20 °C
= mass of calorimeter = 500 g
= specific heat of calorimeter = 0.10 cal/g°C
= Initial temperature of calorimeter = 20 °C
= Final equilibrium temperature
Using conservation of heat
Heat lost by lump of metal = heat gained by water + heat gained by calorimeter
