Which quantity is scalar?<br> (1)velocity (2)speed (3)displacement (4) acceleration

The mass of Venus is 81.5% that of the earth, and its radius is 94.9% that of the earth. If a rock weighs 75.0 N on earth, compu

IgorLugansk [536]

Answer:

g = 0.905 gE

W = 67.9 N

Explanation:

given data

mass of Venus mv = 81.5% = 0.815

radius Rv = 94.9% = 0.949

weighs W = 75.0 N

solution

we apply here acceleration due to gravity at earth surface that is

g = $\frac{Gm}{R^2}$ = 9.80 m/s² ............1

so

g = $\frac{G(0.815)}{0.949R^2}$

g = 0.905 gE

and

W = m gv

W = 0.905 m gE

W = 0.905 × 75

W = 67.9 N

7 0

2 years ago

A 21200 kg sailboat experiences an eastward force 42700 N due to the tide pushing its hull while the wind pushes the sails with

My name is Ann [436]

Answer:

$2.95 m/s^{2}$

Explanation:

The resultant force F

$F=\sqrt {F_{1}^{2}+F_{2}^{2}+2F_{1}F_{2}cos135^{o}}$ where $F_{1}$ is eastward force, $F_{2}$ is force directed towards the North

$F=\sqrt {42700^{2}+85000^{2}+(2*42700*85000)cos135^{o}}=62573.17217 N$

F=62573.2 N

The magnitude of acceleration of sailboat is given by

$a=\frac {F}{m}=\frac {62573.2}{21200}=2.95 m/s^{2}$

7 0

2 years ago

A bar 4.0m long weights 400 N. Its center of gravity is 1.5m from on end. A weight of 300N is attached at the light end. What ar

Debora [2.8K]

Answer:

The resulting, needed force for equilibrium is a reaction from a support, located at 2.57 meters from the heavy end. It is vertical, possitive (upwards) and 700 N.

Explanation:

This is a horizontal bar.

For transitional equilibrium, we just need a force opposed to its weight, thus vertical and possitive (ascendent). Its magnitude is the sum of the two weights, 400+300 = 700 N, since weight, as gravity is vertical and negative.

Now, the tricky part is the point of application, which involves rotational equilibrium. But this is quite simple if we write down an equation for dynamic momentum with respect to the heavy end (not the light end where the additional weight is placed). The condition is that the sum of momenta with respect to this (any) point of the solid bar is zero:

$0=\Sigma_{i}M=400\cdot1.5+300\cdot4-d\cdot700$

Where momenta from weights are possitive and the opposed force creates an oppossed momentum, then a negative term. Solving our unknown d:

$d=\frac{400\cdot1.5+300\cdot4}{700} =2.57 m$

So, the resulting force is a reaction from a support, located at 2.57 meters from the heavy end (the one opposed to the added weight end).

8 0

2 years ago

The 8 kg block is then released and accelerates to the right, toward the 2 kg block. The surface is rough and the coefficient of

natita [175]

Answer:

3.258 m/s

Explanation:

k = Spring constant = 263 N/m (Assumed, as it is not given)

x = Displacement of spring = 0.7 m (Assumed, as it is not given)

$\mu$ = Coefficient of friction = 0.4

Energy stored in spring is given by

$U=\dfrac{1}{2}kx^2\\\Rightarrow U=\dfrac{1}{2}\times 263\times 0.7^2\\\Rightarrow U=64.435\ J$

As the energy in the system is conserved we have

$\dfrac{1}{2}mv^2=U-\mu mgx\\\Rightarrow v=\sqrt{2\dfrac{U-\mu mgx}{m}}\\\Rightarrow v=\sqrt{2\dfrac{64.435-0.4\times 8\times 9.81\times 0.7}{8}}\\\Rightarrow v=3.258\ m/s$

The speed of the 8 kg block just before collision is 3.258 m/s

7 0

2 years ago

A system uses 2380 I of energy to do work as 12,900 j of heat are added to the system. The change in internal energy of the syst

sergey [27]

The internal energy of the system is characterized by the equation U = Q + W where U is the internal energy, Q is the heat and W is work. You are given 2,380 J of energy to do work as 12,900 J of heat so add up. The internal energy is 15,280J.

4 0

2 years ago

Which quantity is scalar? (1)velocity (2)speed (3)displacement (4) acceleration