PLEASE HELP ME WITH THIS ONE QUESTION

A 81 kg man is riding on a 40 kg cart traveling at a speed of 2.3 m/s. He jumps off with zero horizontal speed relative to the g

Alexus [3.1K]

Answer:

$\Delta v= 4.66\frac{m}{s}$

Explanation:

In this case we have to use the Principle of conservation of Momentum:

This principle says that in a system the total momentum is constant if no external forces act in the system. The formula is:

$m_1v_1+m_2v_2=m_1u_1+m_2u_2$

Where:

$m_1:$ Mass of the first object.

$m_2:$ Mass of the second object.

$v_1:$ Initial velocity of the first object.

$v_2:$ Initial velocity of the second object.

$u_1:$ Final velocity of the first object.

$u_2:$ Final velocity of the second object.

In this problem we have:

$m_1=81kg\\m_2=40kg\\v_1_2=2.3\frac{m}{s}$

$u_1=0\frac{m}{s}$

Observation: $v_1_2:$ Is because the system has the same initial velocity.

First we have to find $u_2$ ,

$m_1v_1+m_2v_2=m_1u_1+m_2u_2$

We can rewrite it as:

$(m_1+m_2)v_1_2=m_1u_1+m_2u_2$

Replacing with the data:

$(m_1+m_2)v_1_2=m_1u_1+m_2u_2\\\\(81kg+40kg)2.3\frac{m}{s}=81kg(0\frac{m}{s})+40kg(u_2)\\\\(121kg)2.3\frac{m}{s}=40kg(u_2)\\\\\frac{(121kg)2.3\frac{m}{s}}{40kg}=u_2\\\\\frac{278.3}{40}\frac{m}{s}=u_2\\\\6.96\frac{m}{s}=u_2$

We found the final velocity of the cart, but the problem asks for the resulting change in the cart speed, this means:

$\Delta v=u_2-v_2\\\Delta v=6.96\frac{m}{s}-2.3\frac{m}{s}\\\Delta v= 4.66\frac{m}{s}$

Then, the resulting change in the cart speed is:

$\Delta v= 4.66\frac{m}{s}$

5 0

3 years ago

Please help!! :)

Andrews [41]

Answer:

Option D. 9.47 V

Explanation:

We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 Ω

Resistor 2 (R₂) = 30 Ω

Resistor 3 (R₃) = 45 Ω

Equivalent Resistance (R) =?

R = R₁ + R₂ + R₃ (series connections)

R = 20 + 30 + 45

R = 95 Ω

Next, we shall determine the current in the circuit. This can be obtained as follow:

Voltage (V) = 45 V

Equivalent Resistance (R) = 95 Ω

Current (I) =?

V = IR

45 = I × 95

Divide both side by 95

I = 45 / 95

I = 0.4737 A

Finally, we shall determine, the voltage across R₁. This can be obtained as follow:

NOTE: Since the resistors are in series connection, the same current will pass through them.

Current (I) = 0.4737 A

Resistor 1 (R₁) = 20 Ω

Voltage 1 (V₁) =?

V₁ = IR₁

V₁ = 0.4737 × 20

V₁ = 9.47 V

Therefore, the voltage across R₁ is 9.47 V.

8 0

3 years ago

Can someone check my answers pls

o-na [289]

Hmmm... I’d say that’s pretty accurate. Good job! Well wishes on whatever it is you’re doing.

7 0

4 years ago

Two identical light springs with spring constant k3 are now individually hung vertically from the ceiling and attached at each e

anyanavicka [17]

Answer:

Keq = 2k₃

Explanation:

We can solve this exercise using Newton's second one

F = m a

Where F is the eleatic force of the spring F = - k x

Since we have two springs, they are parallel or they are stretched the same distance by the object and the response force Fe is the same for the spring age due to having the same displacement

F + F = m a

k₃ x + k₃ x = m a

a = 2k₃ x / m

To find the effective force constant, suppose we change this spring to what creates the cuddly displacement

Keq = 2k₃

6 0

3 years ago

As you move further from a light source, the photons of light spread out over a larger distance. In other words, the light _____

frutty [35]

Answer:

INTENSITY, TOWARD THE SUN, 45 J

Explanation:

8 0

3 years ago