Ask question

Ask question

All categories

3 years ago

7

A student slides a book across a desk, with a velocity of +8 m/s. When her friend catches the book, it has a velocity of +7.4 m/

s. If the acceleration was a constant -5.6 m/s2, how wide is the desk?

1 answer:

777dan777 [17]3 years ago

3 0

kinematic equation

v^2=u^2+2*a*s

7.4^2=8^2-2*5.6^2*width

(7.4^2-64)/(2*5.6^2)=-width

You might be interested in

কে প্রথম Anti particle এর অস্তিত্ব ঘোষণা করেন?

const2013 [10]

Answer:

Is this a joke? Because if ur on brainly for english users you should change that

Explanation:

8 0

2 years ago

Read 2 more answers

A bucket of water with total mass 23 kg is attached to a rope, which in turn is wound around a 0.050-m radius cylinder at the to

Elodia [21]

As we know the relation between linear speed and angular speed as

$v = R\omega$

we will say

$v = 8 m/s$

$R = 0.05 m$

so here we can say that angular speed will be given as

$\omega = \frac{8}{0.05}$

$\omega = 160 rad/s$

so it is rotating at angular speed 160 rad/s

7 0

3 years ago

How can a parked car move?

MariettaO [177]

Add force to unbalance the forces

6 0

3 years ago

A heat pump is to be used for heating a house in winter. The house is to be maintained at 70°F at all times. When the temperatur

Anna35 [415]

Answer:

$\dot{W_{H} } = 4244.48 Btu/h$

Explanation:

Temperature of the house, $T_{H} = 70^{0} F$

Convert to rankine, $T_{H} = 70^{0}+ 460 = 530 R$

Heat is extracted at 40°F i.e $T_{L} = 40^{0}F = 40 + 460 = 500 R$

Calculate the coefficient of performance of the heat pump, COP

$COP = \frac{T_{H} }{T_{H} - T_{L} } \\COP = \frac{530 }{530 - 500 }\\ COP = \frac{530}{30} \\COP = 17.67$

The minimum power required to run the heat pump is given by the formula:

$\dot{W_{H} } = \frac{\dot{Q_{H} }}{COP} \\$ ...............(*)

Where the heat losses from the house, $\dot{Q_{H} } = 75,000 Btu/h$

Substituting these values into * above

$\dot{W_{H} } = \frac{75000}{17.67} \\ \dot{W_{H} } = 4244.48 Btu/h$

3 0

3 years ago

A 2-kg bowling ball sits on top of a building that is 40 meters tall.

Dahasolnce [82]

The bowling ball is at rest, so it only has gravitational potential energy.

Ug = mgy
Ug = (2)(9.8)(40) = 784 J

Need any more help?

6 0

3 years ago

Read 2 more answers