A lead bullet of mass 21 g travelling at a speed of $100 m s^{- 1}$ comes to rest in a wooden block. If no heat is taken away by the wood, then find the raise in temperature of wood specific heat of $l e a d = 0.03 c a l o r i e / g^{\circ} C$

Open in App

Solution

Given that,

Rise temperature $= Δ T$

Mass of the bullet $= m$

Now, the kinetic energy associated with the bullet

$K . E = \frac{1}{2} m v^{2}$

$K . E = \frac{1}{2} \times 0.021 \times {(100)}^{2} = 105 J$

Now, according to law of conservation of energy

Change in kinetic energy of bullet = change in internal energy of wood

$K . E = m s Δ T$

$Δ T = \frac{K . E}{m s} = \frac{105 J}{21 \times 0.03 \times 4.2} = 39.68^{o} C$

Hence, the rise temperature of bullet is $39.68^{o} C$

Suggest Corrections

Similar questions

Q. A lead bullet of

10 g

travelling with

300 m / s

strikes against a block of wood and comes to rest. Assuming

60

% of heat is absorbed by the bullet, the increase in its temperature is (Specific heat of Lead is

150

g^{- 1} k^{- 1}

Q. A lead bullet at

100^{o} C

strikes a block of wood, gets embedded in it and melts. Find the speed of the bullet if 50% of the heat produced is shared by the bullet. Specific heat of lead

= 0.03 c a l / g^{o} C

, latent heat of lead

= 5 c a l / g

and melting point of lead

= 327^{o} C

Q. A lead bullet travelling at 210m/s enters a block of wood and is brought to rest. Assuming 75% of heat absorbed by the bullet, calculate the increase in temperature (Specific heat of lead 0.03 X 103 cal/kg

^{o} C

and J

=

4.2 X

10^{3}

J/K-Cal) nearly

A bullet of mass 20 g travelling horizontally with a velocity of 100 m $s^{- 1}$ strikes a wooden block and comes to rest in 0.05 s. Calculate the magnitude of force in N exerted by the wooden block on the bullet.

Q. A bullet of mass

5 g

, travelling with a speed of

210 m/s

, strikes a fixed wooden target. One half of its kinetic energy is converted into heat in the bullet while the other half is converted into heat in the wood. The rise of temperature of the bullet, if the specific heat of its material is

0.030 cal/(g°C)

(1 cal = 4.2 \times 10^{7} ergs

) close to

Join BYJU'S Learning Program

A lead bullet of mass 21 g travelling at a speed of 100ms−1 comes to rest in a wooden block. If no heat is taken away by the wood, then find the raise in temperature of wood specific heat of lead=0.03 calorie/g∘C

A lead bullet of mass 21 g travelling at a speed of $100 m s^{- 1}$ comes to rest in a wooden block. If no heat is taken away by the wood, then find the raise in temperature of wood specific heat of $l e a d = 0.03 c a l o r i e / g^{\circ} C$