Question

1. a force of 500 n is used to pull an object up an inclined plane. in order to raise the object, the total amount of work done was 1500 joules. calculate the distance the object was moved. show your work. include proper units in your answer.

answer:

1. calculate the amount of work done when a 70 kg person is lifted a vertical distance of 1.5 meters. (don’t forget to convert mass to force of gravity first) show your work. include proper units in your answer.

answer:

1. consider the following diagram of a ramp.

diagram of a ramp with a 70 kg object, a force f = 100 n, length of ramp 14 m, vertical height 2 m

a. calculate the force of gravity on the 70 kg object. ______ n
b. calculate the work which would be done to raise the 70 kg mass straight up a vertical distance of 2 meters. (that is, without using the ramp.)
answer: ______ j
c. calculate the work done when the object is moved 14 meters up the ramp using a force of 100 n.
answer: ______ j
d. what is the advantage of using a ramp like this to move an object up instead of lifting it straight up?

Explanation:

Problem 6

Step1: Recall work formula

Work is defined as $W = F \times d$, rearrange for distance.

Step2: Solve for distance

$d = \frac{W}{F} = \frac{1500\ \text{J}}{300\ \text{N}}$
---

Problem 7

Step1: Calculate gravitational force

$F_g = m \times g$, use $g=9.8\ \text{m/s}^2$.
$F_g = 70\ \text{kg} \times 9.8\ \text{m/s}^2$

Step2: Calculate work done

$W = F_g \times h$, $h=1.2\ \text{m}$
$W = (70 \times 9.8)\ \text{N} \times 1.2\ \text{m}$
---

Problem 8a

Step1: Calculate gravity force

$F_g = m \times g$, $g=9.8\ \text{m/s}^2$
$F_g = 70\ \text{kg} \times 9.8\ \text{m/s}^2$
---

Problem 8b

Step1: Use work-gravity formula

$W = F_g \times h$, $h=2\ \text{m}$
$W = (70 \times 9.8)\ \text{N} \times 2\ \text{m}$
---

Problem 8c

Step1: Use work-force-distance formula

$W = F \times d$, $F=100\ \text{N}$, $d=14\ \text{m}$
$W = 100\ \text{N} \times 14\ \text{m}$
---

Problem 8d

Step1: Explain ramp mechanical advantage

Ramps reduce required applied force.

A ramp acts as an inclined plane, a simple machine that reduces the amount of force needed to move an object to a higher elevation, even though the total work done is approximately the same as lifting it straight up.

Answer:

Problem 6:

$\frac{1500}{300} = 5$
Final Answer: $\boldsymbol{5\ \text{meters}}$

Problem 7:

$F_g = 686\ \text{N}$, $W = 686 \times 1.2 = 823.2$
Final Answer: $\boldsymbol{823.2\ \text{Joules}}$

Problem 8a:

$70 \times 9.8 = 686$
Final Answer: $\boldsymbol{686\ \text{N}}$

Problem 8b:

$686 \times 2 = 1372$
Final Answer: $\boldsymbol{1372\ \text{Joules}}$

Problem 8c:

$100 \times 14 = 1400$
Final Answer: $\boldsymbol{1400\ \text{Joules}}$

Problem 8d: