Ask question

Ask question

All categories

2 years ago

9

3. A driver who is moving at 15 m/s, sees a stop light and puts on the brakes 30 m before an intersection. a) What acceleration

will the driver have to have to stop before entering the intersection? b) How much time will it take to stop the car?

1 answer:

Nesterboy [21]2 years ago

4 0

Please find attached photograph for your answer. Hope it helps! Please do comment

You might be interested in

The top priority in a lab setting is

SpyIntel [72]

The answer is a.safety

5 0

3 years ago

An object moving at 36 km/h reduces its speed to 18 km/h in 2sec. If the mass of the object is 20 kg, find the average force act

laiz [17]

Answer:

-50 N

Explanation:

Givens:

V_i = 36 km/h

V_f = 18 km/h

t = 2 s

m = 20 kg

First we have to convert our km/h into m/s:

(36 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 10 m/s

(18 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 5 m/s

a = (V_f - V_i)/t

a = (5 m/s - 10 m/s) / 2 s

a = -2.5 m/s^2

F = m(a)

F = 20 kg(-2.5 m/s^2)

F = -50 N

It's a negative force meaning its acting on it opposite its current direction of movement.

7 0

3 years ago

A boy whirls a stone in a horizontal circle of radius 1.50m and at height 2.00m above level ground. The string breaks, and the s

Eddi Din [679]

Answer:

$a_{cp}=162.2m/s^2$

Explanation:

The time the stone takes to fall can be calculated considering only the vertical component with the formula:

$y=y_0+v_{0y}t+\frac{a_yt^2}{2}$

Taking the inital height as 0m and downward direction positive, since it departs from (vertical) rest we have:

$y=\frac{gt^2}{2}$

Which gives us a time:

$t=\sqrt{\frac{2y}{g}}=\sqrt{\frac{2(2m)}{(9.8m/s^2)}}=0.64s$

Horizontally, on that time the stone travelled a distance x=10m, which means its horizontal speed was:

$v_x=\frac{x}{t}=\frac{10m}{0.64s}=15.6m/s$

Since <u>this speed is the tangential velocity</u> while whirling, the centripetal acceleration of the stone was:

$a_{cp}=\frac{v_x^2}{r}=\frac{(15.6m/s)^2}{(1.5m)}=162.2m/s^2$

7 0

3 years ago

What is one property that all particles of matter have in common?

Mars2501 [29]

They move c<span>onstantly and are attracted to one another. Describe solids, liquids, and gases in terms of shape and volume. Solids have </span>definite<span> shape and volume.</span>

5 0

3 years ago

in coal-fired power plants, coal is burned to produce ____________________, which is then used to turn a turbine.

crimeas [40]

The answer is STEAM.

6 0

3 years ago

Read 2 more answers