Answer:
6.18 m/s
Explanation:
Roller skate collision
The final direction of the system (me=M + person=P) velocity vector is at an angle; Ф, to the direction running south to north. Apply the component form of the impulse-momentum equation, firstly;
x-axis component form (+x east);
+ 
+ 
= 
+
Ф
60 ·8 + 0 = (60 + 80)
Ф
480 = 140
Ф................. (I)
y-axis component form (+y north);
+ 
+ 
= 
+ 
Ф
0 + 80.9 = (60 + 80)
Ф
720=
140Ф
140Vf=
Ф......................................(2)
Substituting (2) into (1) to give the angle;
480 = 720tan Ф
Ф = arctan(0.67) =33.69°.......................(3)
Evaluating (1) with (3) gives the velocity magnitude
480 = 140Vfsin 33.69°
Vf=6.18 m/s
note 1:
This angle corresponds to a direction; 90° - 33.69° = 56.31° north of east.
Answer:
0.775
Explanation:
The weight of an object on a planet is equal to the gravitational force exerted by the planet on the object:
where
G is the gravitational constant
M is the mass of the planet
m is the mass of the object
R is the radius of the planet
For planet A, the weight of the object is
For planet B,
We also know that the weight of the object on the two planets is the same, so
So we can write
We also know that the mass of planet A is only sixty percent that of planet B, so
Substituting,
Now we can elimanate G, MB and m from the equation, and we get
So the ratio between the radii of the two planets is
Answer: A) 2 B) 4 C) 1
Explanation:
The Electric field from a parallel-plate capacitor is given by:
A) E=Q/(L^2 * ε0) so if we put a charge double the final electric field is double that the original.
B) from the above expression for the electric field, If the size of the plate is double, then the E final is four times weaker that the original.
C) If the distante between plates is doubled the final electric field is the same that initial.
Answer:
Explanation:
It is given that,
Mass of the puck, m = 4.8 kg
Initial velocity of the puck, 
After 8 seconds, final velocity of the puck, 
Let the x and y component of force is given by 
.
x component of force is given by :
y component of force is given by :
So, the component of the force is . Hence, this is the required solution.
