Ask question

Ask question

All categories

3 years ago

15

"An elevator is moving upward with a speed of 11 m/s. Three seconds later, the elevator is still moving upward, but its speed ha

s been reduced to 5.0 m/s. What is the average acceleration of the elevator during the 3.0 s interval?

1 answer:

ehidna [41]3 years ago

5 0

Answer:

Average acceleration = - 2 m/s^2

Explanation:

Given data:

Initial velocity = 11 m/s

Final velocity = 5.0 m/s

duration of change in velocity = 3 sec

Average acceleration $= \frac{v - u}{\Delta t}$

Average acceleration $= \frac{5 - 11}{3} = -2 m/s^2$

Average acceleration = - 2 m/s^2

here negative sign indicate that acceleration is proceed in downward direction.

You might be interested in

muminat

Answer: a force is simply a push or pull.

The SI unit for force is Newton(N) or kgm/s2

When the net force on an object is not zero the forces are said to be unbalanced since they do not cancel out each other .

When two forces act in opposite directions we substract the forces in order to get the resultant force acting on the object.

Explanation:

8 0

3 years ago

Read 2 more answers

The following time dependent force is applied to a 2 kg block that is initially at rest on a frictionless and horizontal surface

DerKrebs [107]

Answer:

The displacement of the block is 9 m.

Explanation:

Given that,

Mass of block = 2 kg

Time = 3 sec

The force is

$F(t)=4t$

The acceleration is

$a=\dfrac{F}{m}$

Put the value into the formula

$a=\dfrac{4t}{2}$

$a=2t$

We need to calculate the velocity

Using formula of acceleration

$v=\int_{0}^{t}{a dt}$

Put the value into the formula

$v=\int_{0}^{3}(2t dt)$

$v=(\dfrac{2t^2}{2})_{0}^{3}$

$v=(t^2)_{0}^{3}$

$v=9\ m/s$

We need to calculate the displacement

Using formula of velocity

$s=\int_{0}^{3}(v dt)$

$s=(t^2)_{0}^{3}$

$s=(\dfrac{t^3}{3})_{0}^{3}$

$s=9\ m/s$

Hence, The displacement of the block is 9 m.

8 0

3 years ago

Read 2 more answers

When charges build up on a surface they:

NeTakaya

The awnser is A and B

6 0

4 years ago

a 2700-ohm reisstor in an electric circuit draws a current of 2.4 milliamperes. the total charge that passes through the reisito

svetoff [14.1K]

R = 2700 ohm
I = 2.4 mA = 2.4 × 10^(-3) A
I = Q/t
Q = I × t = 2.4 × 10^(-3) × 15 s = 36 C

5 0

4 years ago

A ball is thrown downward from the top of a building with an initial speed of 25 m/s.

Bumek [7]

Answer:

h = 69.6 m

Explanation:

Data:

Vo = 25 m/s
t = 2.0 s
g = 9.8 m/s²
h = ?

Formula:

$\boxed{\bold{h=V_{0}*t+\frac{g*(t)^{2}}{2}}}$

Replace and solve:

$\boxed{\bold{h=25\frac{m}{s}*2.0\ s+\frac{9.8\frac{m}{s^{2}}*(2.0\ s)^{2}}{2}}}$

$\boxed{\bold{h=50\frac{m}{s^{2}}+\frac{9.8\frac{m}{s^{2}}*4\ s^{2}}{2}}}$

$\boxed{\bold{h=50\ m+\frac{39.2\ m}{2}}}$

$\boxed{\bold{h=50\ m+19.6\ m}}$

$\boxed{\boxed{\bold{h=69.6\ m}}}$

The building has a height of <u>69.6 meters.</u>

Greetings.

5 0

3 years ago