Question

please answer 1 and 2

Cablc Rope 2 2. Two blocks are on a horizontai, frictionless . The figure above shows a truck pulling thrce crates across a rough road. Which of the following shows the directions of all the horizontal forces acting on crate 2 ? surface. Block A is moving with an initial velocity of o toward block B. which is stationary, as shown above. The two blocks collide, stick together, and move off with a velocity of o/3.Which block, if either, has the greater mass? (A) Block A (B) Block B (C) Neither: their masses are the same. (D) The answer cannot he determined without Cable Rope (B) Rope Cable Crate ? (C) Rope Crue 3 Iriction Cable knowing the mass of onc of the blocks. (D) Rupe Cable Crate 3 Friction

Answer 1

(1)

Cable is pulling the block towards right.

Friction due to the surface will oppose this motion. i.e friction will be towards left.

Rope connecting the block 2 and block 3 is pulling block2 towards left.

Their is normal reaction due to block1 on block2 towards left.

Hence answer is (c)

(2)

Given,

Speed of block A before collision is v₀

Speed of block B before collision is zero.

They stick together and speed is v₀/3

let mass of block A be m_A

let mass of block B be m_B

Now,

Applying conservation of momentum

=> m_A*v₀ + m_B*0 = (m_A+m_B)*(v₀/3)

=> m_A*v₀ = (m_A+m_B)*(v₀/3)

=> m_A = (m_A+m_B)/3

=> 3*m_A = m_A+m_B

=> 2*m_A = m_B

=> m_A = m_B/2

So, we can see that m_B>m_A

Hence, answer is (B)