Ask question

Ask question

All categories

4 years ago

10

A 900-N lawn roller is to be pulled over a 5-cm (high) curb. Radius of roller is 25 cm. What minimum pulling force is needed if

angle made by handle is (a) 0 deg (b) 30 degrees?

1 answer:

Feliz [49]4 years ago

8 0

I believe b 30 degrees

You might be interested in

ivolga24 [154]

A metaphor is<span> a comparison between two non related objects where the first object is said to be equal to the second.</span>

The answer is d.

6 0

3 years ago

A train 4.00 3 102 m long is moving on a straight track with a speed of 82.4 km/h. The engineer applies the brakes at a crossing

zysi [14]

Answer:

The value is $t =29.2 \ s$

Explanation:

From the question we are told that

Generally the average velocity of the train is mathematically represented as

$v = \frac{u + v}{2}$

substituting 82.4 km/h for u and 16.4 km/h. for v

$v = \frac{82.4 + 16.4}{2}$

$v = 49.4 \ km/h$

Generally the time taken is mathematically represented as

$t = \frac{ L}{v}$

substituting 49.4 \ km/h for v and $4.00 * 10^2 \ m = 0.400 \ km$

$t = \frac{ 0.400}{49.4}$

$t = 0.00809 \ h$

converting to seconds

$t = 0.00809 * 3600$

$t =29.2 \ s$

7 0

3 years ago

Which of the following is an example of potential energy?

tigry1 [53]

The answer is b because it’s something being stretched and it

7 0

3 years ago

Read 2 more answers

A helicopter lifts a 72 kg astronaut 15 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/

NemiM [27]

Answer:

a) $F_H=776.952\ N$

b) $F_g=706.32\ N$

c) $v=5.4249\ m.s^{-1}$

d) $KE=1059.48\ J$

Explanation:

Given:

mass of the astronaut, $m=72\ kg$

vertical displacement of the astronaut, $h=15\ m$

acceleration of the astronaut while the lift, $a=\frac{g}{10} =0.981\ m.s^{-2}$

a)

<u>Now the force of lift by the helicopter:</u>

Here the lift force is the resultant of the force of gravity being overcome by the force of helicopter.

$F_H-F_g=m.a$

where:

$F_H=$ force by the helicopter

$F_g=$ force of gravity

$F_H=72\times 0.981+72\times9.81$

$F_H=776.952\ N$

b)

The gravitational force on the astronaut:

$F_g=m.g$

$F_g=72\times 9.81$

$F_g=706.32\ N$

d)

Since the astronaut has been picked from an ocean we assume her initial velocity to be zero, $u=0\ m.s^{-1}$

using equation of motion:

$v^2=u^2+2a.h$

$v^2=0^2+2\times 0.981\times 15$

$v=5.4249\ m.s^{-1}$

c)

Hence the kinetic energy:

$KE=\frac{1}{2} m.v^2$

$KE=0.5\times 72\times 5.4249^2$

$KE=1059.48\ J$

8 0

3 years ago

Read 2 more answers

A yellow ball with a mass of 2 kg is rolling across the floor at 3 m/s. A red ball with a mass of 3 kg is rolling across the sam

Amiraneli [1.4K]

Answer:B The red ball has greater kinetic energy because it has greater mass

Explanation:

3 0

3 years ago

Read 2 more answers