Question

2. The modulus of vector 5î + 7j - 2k is
3. Linear momentum
x velocity​

Answer 1

2) √(5²+7²+2²) = √78

3) Energy

Answer 2

Given,
r=
i
^
−2
j
^
​
+
k
^

p=2
i
^
−
j
^
​
+
k
^

Angular momentum
J=r×p
=(
i
^
−2
j
^
​

k
^
)×(2
i
^
−
j
^
​
+
k
^
)
J=
i
^
(−2+1)−
j
^
​
(1−2)+
k
^
(−1+4)
J=−
i
^
+
j
^
​
+3
k
^