Question

name:
newtons second law
equation
force = mass x acceleration
force of gravity = mass x 9.8
units
force - n
date: 10/9 period: 2a

1. calculate the force of gravity of a 10 kg firework.
2. calculate the force of gravity of a 150 kg man skydiving.
3. a 3 kg rock is dropped from a cliff. what is the force of gravity?
4. a 0.10 kg baseball falls to earth from a pop fly. what is the force of gravity?
5. a little boy pushes a wagon with his dog in it. the mass of the dog and wagon together is 45 kg. the wagon accelerates at 0.85 m/s². what force is the boy pulling with?
6. a 1650 kg car accelerates at a rate of 4.0 m/s². how much force is the cars engine producing?
7. a tennis ball, 0.314 kg, is accelerated at a rate of 164 m/s² when hit by a professional tennis player. what force does the players tennis racket exert on the ball?

Explanation:

Step1: Recall the formula for force of gravity

$F = mg$, where $m$ is mass and $g=9.8\ m/s^{2}$ for force of gravity. For other forces, use $F = ma$, where $a$ is acceleration.

Step2: Solve problem 1

Given $m = 10\ kg$, $F=mg=10\times9.8 = 98\ N$

Step3: Solve problem 2

Given $m = 150\ kg$, $F=mg=150\times9.8=1470\ N$

Step4: Solve problem 3

Given $m = 3\ kg$, $F=mg=3\times9.8 = 29.4\ N$

Step5: Solve problem 4

Given $m = 0.10\ kg$, $F=mg=0.10\times9.8=0.98\ N$

Step6: Solve problem 5

Given $m = 45\ kg$, $a = 0.85\ m/s^{2}$, $F=ma=45\times0.85 = 38.25\ N$

Step7: Solve problem 6

Given $m = 1650\ kg$, $a = 4.0\ m/s^{2}$, $F=ma=1650\times4.0=6600\ N$

Step8: Solve problem 7

Given $m = 0.314\ kg$, $a = 164\ m/s^{2}$, $F=ma=0.314\times164 = 51.496\ N$

Answer:

1. $98\ N$
2. $1470\ N$
3. $29.4\ N$
4. $0.98\ N$
5. $38.25\ N$
6. $6600\ N$
7. $51.496\ N$