Which of these determines an objects ability to sink or float in water?

3. An object of mass 90 kg travels down a slide.

Zolol [24]

Gpe= 90* 9.81 * 15 = 13243.5 Joules

KE= 13243.5 =1/2 m v^2
v^2= 295.3
v= 17.2 m/s

6 0

3 years ago

Train cars are coupled together by being bumped into one another. Suppose two loaded cars are moving toward one another, the fir

tia_tia [17]

Answer:

7560 Joules

Explanation:

$m_1$ = Mass of first car = $1.5\times 10^5\ kg$

$m_2$ = Mass of second car = $2\times 10^5\ kg$

$u_1$ = Initial Velocity of first car = 0.3 m/s

$u_2$ = Initial Velocity of second car = -0.12 m/s

v = Velocity of combined mass

As linear momentum of the system is conserved

$m_1u_1 + m_2u_2 =(m_1 + m_2)v\\\Rightarrow v=\frac{m_1u_1 + m_2u_2}{m_1 + m_2}\\\Rightarrow v=\frac{1.5\times 10^5\times 0.3 + 2\times 10^5\times -0.12}{1.5\times 10^5 + 2\times 10^5}\\\Rightarrow v=0.06\ m/s$

Energy lost is

$\Delta E=\Delta E_i-\Delta E_f\\\Rightarrow \Delta=\frac{1}{2}(m_1u_1^2 + m_2u_2^2-(m_1+m_2)v^2)\\\Rightarrow \Delta=\frac{1}{2}(1.5\times 10^5\times 0.3^2 + 2\times 10^5\times (-0.12)^2-(1.5\times 10^5 + 2\times 10^5)\times 0.06^2)\\\Rightarrow \Delta=7560\ J$

The Energy lost in the collision is 7560 Joules

7 0

3 years ago

Acceleration is always measured in meters per second squared. Why is acceleration not measured in meters per second like speed?

Taya2010 [7]

Answer:

Because 'distance per second' is a velocity, not an acceleration.

Explanation:

Because 'distance per second' is a velocity, not an acceleration. For example, at 1 m/s an object is travelling a distance of 1 metre every second. But a rate of acceleration is a steady increase in velocity. So at 1 m/s^2, an object's velocity is increasing by 1 m/s every second.

6 0

2 years ago

You do 45.0 joules of work and 3.00 seconds how much power do you use

Arada [10]

Answer:

15 watt

Explanation:

Power is the rate at which work is done.

This means you divide the work done with the amount of time used to perform the work.

The formula for Power is : P = W/t where;

W= work done in J = 45

t= time in seconds = 3 sec

P= 45/ 3 = 15 watt

8 0

3 years ago

George is applying a downward force of 50N to and object that has a mass of 50kg. What is the normal force (FN) of the object wh

attashe74 [19]

The normal force acting on the object is 500 N in the upward direction

<u>Explanation:</u>

As George is applying a downward force, the normal force will be in the upward direction. The normal force will be exerted due to the acceleration due to gravity exerted on the object.

So, as per Newton's second law, the normal force acting on the object can be measured by the product of mass of the object and the acceleration due to gravity acting on the object.

But as the acceleration due to gravity is a downward acting acceleration and the normal force is a upward acting force, so the acceleration will be having a negative sign in the formula.

$Normal\ force = Mass \times Acceleration\ due\ to\ gravity$

Here, acceleration due to gravity g = -10 m/s² and mass is given as 50 kg, then

Normal force = 50 × (-10) = -500 N

So, the normal force acting on the object is 500 N in the upward direction.

3 0

3 years ago