Question

amy uses 20 n of force to push a lawn mower 10 meters. how much work does she do? (question 1)
21m

a baby carriage is sitting at the top of a hill that is 21 m high. the carriage with the baby has a mass of 22 kg. calculate the potential energy. (question 6)
your answer

a car is traveling with a velocity of 40 m/s and has a mass of 1120 kg. calculate the kinetic energy. (question 7)
your answer

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Explanation:

Question 1: Work Calculation

Step1: Recall Work Formula

Work ($W$) is calculated as $W = F \times d$, where $F$ is force and $d$ is distance.

Step2: Substitute Values

Given $F = 20\ N$ and $d = 10\ m$, so $W = 20 \times 10$.

Step3: Calculate Result

$20 \times 10 = 200\ J$ (Joules, unit of work).

Step1: Recall PE Formula

Gravitational Potential Energy ($PE$) is $PE = mgh$, where $m$ is mass, $g = 9.8\ m/s^2$ (acceleration due to gravity), and $h$ is height.

Step2: Substitute Values

Given $m = 22\ kg$, $g = 9.8\ m/s^2$, $h = 21\ m$. So $PE = 22 \times 9.8 \times 21$.

Step3: Calculate Result

First, $22 \times 9.8 = 215.6$. Then, $215.6 \times 21 = 4527.6\ J$.

Step1: Recall KE Formula

Kinetic Energy ($KE$) is $KE = \frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.

Step2: Substitute Values

Given $m = 1120\ kg$, $v = 40\ m/s$. So $KE = \frac{1}{2} \times 1120 \times (40)^2$.

Step3: Calculate Result

First, $(40)^2 = 1600$. Then, $\frac{1}{2} \times 1120 = 560$. Then, $560 \times 1600 = 896000\ J$.

Answer:

200 Joules

Question 6: Potential Energy Calculation