Question

The third graders are on one side of a schoolyard, and the fourth graders are on the other. They are throwing snowballs at each other. As a result, snowballs of various masses are moving with different velocities, as shown in Figure OQ5.3. Rank the snowballs (a) through (e) according to the magnitude of the total force exerted on each one. Ignore air resistance. If two snowballs rank together, make that fact clear.

Short answer

The ranking of total force exerted on each snowball is$m_d>m_a=m_e>m_b>m_c$ .

Step-by-step solution

Identification of given data

The mass and speed of snowball (a) are$m_a=400\text{g}$ and$u_a=9\text{m/s}$

The mass and speed of snowball (b) are $m_b=300\text{g}$and $u_b=12\text{m/s}$

The mass and speed of snowball (c) are $m_c=200\text{g}$and $u_c=12\text{m/s}$

The mass and speed of snowball (d) are $m_d=500\text{g}$and$u_d=10\text{m/s}$

The mass and speed of snowball (e) are $m_e=400\text{g}$and $u_e=8\text{m/s}$

The gravitational force exerted on each snowball is due to only gravitational acceleration. The gravitational acceleration for each snowball is the same, so the ranking of the total force of each one is done by the mass of the snowball.

Ranking of the total force exerted on each snowball.

The mass of snowball (d) is the highest. The mass of the snowball (a) and (e) are the same and next to the mass of the snowball (d). The mass of the snowball (d) is next to (a) and (e). The mass of snowball (c) is the smallest of all snowballs. The ranking of the total force exerted on each snowball will be the same as the ranking of their masses.

Therefore, the ranking of total force exerted on each snowball is

$m_d>m_a=m_e>m_b>m_c$